It depends what you mean by 'snap' I guess. One silly thing we do with LDraw parts is zoom in to the parts so much that in reality you would need a microscope!!! Real tolerance on bricks is, according to legend, about 1/16 LDU so anything beyond that is pure nerd games 
The longest part I know of is 55 studs long (a flex tube) or 1100LDU long. The maximum error of a rotation with 4 decimal places is 5/1000 meaning that such a rotation would give an error of about 5LDU (which is bad). Taking it to 6 decimal places gives 1/20 LDU, which is less than the tolerance in LEGO.
Ramble, ramble, ramble
Tim
The longest part I know of is 55 studs long (a flex tube) or 1100LDU long. The maximum error of a rotation with 4 decimal places is 5/1000 meaning that such a rotation would give an error of about 5LDU (which is bad). Taking it to 6 decimal places gives 1/20 LDU, which is less than the tolerance in LEGO.
Ramble, ramble, ramble
Tim